The five-month study combined “real on-farm conditions” with “strict scientific controls,” according to lead researcher Judy Carman of Flinders University in Australia.

Using pigs was important not only because “we eat them,” but because humans and pigs share similar digestive systems, Carman said in a statement.

"We need to investigate if people are also getting digestive problems from eating GM crops," the statement said.

In pigs eating genetically modified crops, the average rate of severe stomach inflammation was nearly three times as high as that for other pigs (32 percent vs. 12 percent). Among male pigs eating a GM diet, the rate of severe stomach inflammation was four times higher.